Bolt and nut assembly



April la, 1946. A GAZDA 2,398,633

I Y BOLT AND NUT ASSEMBLY Filed June 14, 1943 www@ Patented Apr. 16, 1946 BoL'r AND NUT ASSEMBLY Antoine Gazda, Providence, R. I.

Application June 14, 1943, Serial No. 490,789

Claims. (Cl. 151-31) bled parts being effected by means 'of a nut threaded onto the free projecting end of the bolt. Frequently, however, as a result of disturbing inuences such as vibrations and the like, the retaining nut is loosened and/or wholly dislodged, with manifestly undesirable results. Resort has been made with a greater or less degree of success to many expedients such as lock nuts and the like,'in an eiort to overcome the aforedescribed diillculty.

This invention provides a method and means for obviating the said diiiiculty without, however, having to employ additional parts such as an extraneous lock nut, lock washer or the like, by the simple expedient of assembling the parts and then expanding or spreading that portion of preferred embodiments -of the-invention, taken in the light of the accompanying sheet of drawings:

On the said sheet of drawings,

Fig. 1 is a view, partly in section and partly in elevation, of a nut and bolt assembly-the bolt being constructed in accordance with the principles of the present inventionprior to the expansion ofthe outer bolt end;

Fig. 2 is a view, partly in section and partly in elevation, of the nut and bolt assembly of 1, after expansion of the outer bolt end; Fig. 3 is a view, partly in section and partly in elevation, of a nut and bolt assembly, involving a modified form of bolt constructed according to the principles of this invention, prior to expansion of the projecting bolt end; and

Fig. 4 is a view, partly in section and partly in elevation, showing the assembly of Fig. 3 after expansion of the bolt end.

Corresponding parts are designated by corresponding reference characters throughout the several figures of drawing.

Referring now to Figs. l and 2 of the drawing, this illustrates a relationship of parts comprising a pair of members to be bolted together, and bolt and nut means for effecting such bolting. The pair of members, designated by reference characters I0 and Il, typify any plurality of parts which are to be held in assembled relationship. They may, for example, represent two parts of a -machine which is exposed to strong vibratory forces, or they may represent juxtaposed airplane parts which are subject to considerable vibration tending to loosen and dislodge the nut of a conventional nut and bolt assembly.

rlhe nut and bolt means, according to the embodiment of Figs. l and 2, comprises a conventional nut I2 associated, as shown and hereinafter explained, with bolt I3. Bolt i3 may include the usual polygonal head Id, or other conventional bolt head construction, at one end of the bolt shank which may be exteriorly threaded along the major extent thereof, as at l5.

The outer or free end of the bolt shank is constructed according to the principles of the present invention as applied to a bolt made, for example, of duralumin, non-hardened steel or the like, and of relatively small diameter,-this being the type of bolt shown in Figs. l and 2 of the drawing.

' As shown in the latter, the outer or free end of the bolt shank is provided with an undercut recess I6 of suitable'configuration, which prefer-` Recess I6 is lled with an explosive chemical composition II of any suitable and/or desired character. For example, use may be made of a trinitrotoluol paste which is capable of explosion upon detonation or upon being fired by any other suitable means, as for instance by being touched with a hot instrument.

Explosion of the composition I'I will result in a bulging' out of the wall encompassing recess I6, as shown at I8 in Fig. 2, the result being to lock nut I2 in place between member Il and bulge I8. Head Hl having previously been drawn into close juxtaposition to member I 0, the parts are securely retained in the desired assembled`relationship.

An important feature is the conguration of the recess IB and the disposition of thewider end g tion.)

thereof interlorly of the bolt. This is prerequisite to the formation of bulge I8, since 'otherwise the explosive composition II would merely blow out of recess IB and would notcause the expansion of the end of the bolt extending beyondv the nut.

Figs. 3 and 4 illustrate a modification of the relationship of parts according to this invention, particularly adapted in connection with bolts made of high alloy steel or of relatively large diameter.

As in the first embodiment. the members I and I I are held together by bolt I3' provided with head I4' and screw-threaded shank I5' on which is arranged nut I2; see Fig. 3 of the drawing, showing the assembly of these parts prior` to the locking thereof together.

To enable the locking to be effected, the free or projecting end of the bolt is, as in the previously described embodiment. provided with an undercut or frusta-conical recess I6', corresponding to recess I6 of the irst embodiment, which like the latter is filled' with an explosive composition l1. In order to facilitate the spreading of the bolt end, the latter is. in this second form of the invention, provided with'a plurality of cross slots I9-two such slots arranged substantially centrally of the Ibolt end and at substantial right angles to each. other being shown in Figs. 3" and 4. 'I'he result is to subdivide the free shank end into a pluralityin the illustrated case, four-of spreadable segments I8. (For the sake of clearness. the showing on the drawing exaggerates the size of slots I 9. Actually, these slots are very narrow, with the walls thereof in close juxtaposi- In order further to enhance the spreadability of the segments I8', each slot I9 is provided at the bottom thereof with an enlarged rounded bore, as shown at 20, extending all the way across the bolt.

Spreading of the segments I8' into the position being provided with an undercut open-ended recess, which is essentially frusto-conical in configuration. with the smaller end being open, and an explosive composition in said recess.

2. A bolt of the character described comprising a head and a bolt shank extending therefrom, said shank being externally threaded along the major extent thereof, said shank terminatingin a slotted free end, whereby a plurality of outwardly ilarable segments are provided at said end, the free end of said shank being provided with an undercut open-ended recess, which is essentially frustoconical in configuration, with the smaller end being open, and means in said bolt for spreading said segments into outwardlyared position.

3. A bolt of the character described comprising a head and a bolt shank extending therefrom, said shank being externally threaded along the major extent thereof, said shank terminating in a slotted free end, said free end comprising a plurality of slots arranged at an angle with respect to each other, whereby a plurality of outwardly flarable segments are provided at said end, lthe bottom of each said slot terminating in an enlarged bore, the free end of said shank being provided with an undercut open-ended recess, which is essentially frusto-conical in configuration, with the smaller end being open, and means in said bolt for spreading said segments into outwardly iiared position.

4. A bolt of the character described comprising a head and a bolt shank extending therefrom, said shank being externally threaded along the major extent thereof, said shank terminating in a slotted free end, said free end comprising a plurality of slots arranged at an angle with respect to each other, whereby a plurality of outwardly flarable segments are provided at said end, said end being provided with an undercut open-ended recess of frusta-conical configura- '40 tion, with the smaller end being open,and an exshown in Fig. 4 is accomplished by exploding the vwhich accomplishes the objects of the invention.

Having thusidescribed the invention, what is claimed is:

"IIA bolt of the character described comprising a head and an externally threaded bolt shank extending therefrom, the free end of said shank plosive composition i'n said recess.

5. A bolt of the character described comprising a head and a bolt shank extending therefrom, said shank being externally threaded along the major extent thereof, said shank terminating in a slottedv free end, whereby a plurality of outwardly arable segments are provided at said end, the bottom of said slot terminating in an enlarged bore said end being provided with an undercut open-ended recess of frusto-conical configuration, with the smaller end being open, and an explosive composition in said recess.

ANTOINE GAZDA. 

